Experimental Investigation of Superradiance in a Tapered Free-Electron Laser Amplifier

Conference · Mon Mar 28 04:00:00 EDT 2011

OSTI ID:1016650

Hidaka, Y; She, Y; Murphy, J B; Podobedov, B; Seletskiy, S; Yang, X

We report experimental studies of the effect of undulator tapering on superradiance in a single-pass high-gain free-electron laser (FEL) amplifier. The experiments were performed at the Source Development Laboratory (SDL) of National Synchrotron Light Source (NSLS). Efficiency was nearly tripled with tapering. Both the temporal and spectral properties of the superradiant FEL along the uniform and tapered undulator were experimentally characterized using frequency-resolved optical gating (FROG) images. Numerical studies predicted pulse broadening and spectral cleaning by undulator tapering Pulse broadening was experimentally verified. However, spectral cleanliness degraded with tapering. We have performed first experiments with a tapered undulator and a short seed laser pulse. Pulse broadening with tapering expected from simulations was experimentally confirmed. However, the experimentally obtained spectra degraded with tapering, whereas the simulations predicted improvement. A further numerical study is under way to resolve this issue.

• Research Organization: Brookhaven National Laboratory (BNL) National Synchrotron Light Source
• Sponsoring Organization: DOE - OFFICE OF SCIENCE
• DOE Contract Number: AC02-98CH10886
• OSTI ID: 1016650
• Report Number(s): BNL--94971-2011-CP; 39KC02000
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
ACCELERATORS
AMPLIFIERS
CLEANING
EFFICIENCY
FREE ELECTRON LASERS
LASERS
NSLS
SEEDS
SPECTRA
SUPERRADIANCE
WIGGLER MAGNETS
broadening
high-gain
national synchrotron light source
predicted
pulse
single-pass
spectral
superradiance
tapeting
tripled